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Annual growth of fagus orientalis is limited by spring drought conditions in Iran’s Golestan Province

Journal of Forestry Research 2024年第1期35卷 128-142页

作者： Khalil Ghorbani Jahangir Mohammadi Laleh Rezaei Ghaleh Department of Water Engineering Faculty of Water and Soil EngineeringGorgan University of Agricultural Sciences and Natural ResourcesGorganIran Department of Forestry Gorgan University of Agricultural Sciences and Natural ResourcesGorganIran Department of Water Engineering Faculty of AgricultureUrmia UniversityUrmiaIran

Due to the lack of a uniform and accurate defi-nition of‘drought’,several indicators have been introduced based on different variables and methods,and the efficiency of each of these is determined according to their relationship with drought.The relationship between two drought indices,SPI(standardized precipitation index)and SPEI(standard-ized precipitation-evapotranspiration index)in different sea-sons was investigated using annual rings of 15 tree samples to determine the effect of drought on the growth of oriental beech(fagus orientalis Lipsky)in the Hyrcanian forests of northern Iran.The different evapotranspiration calcula-tion methods were evaluated on SPEI efficiency based on Hargreaves-Samani,Thornthwaite,and Penman-Monteith methods using the step-by-step M5 decision tree regression method.The results show that SPEI based on the Penman-Monteith in a three-month time scale(spring)had similar temporal changes and a better relationship with annual tree rings(R^(2)=0.81)at a 0.05 significant level.Abrupt change and a decreasing trend in the time series of annual tree rings are similar to the variation in the SPEI based on the Penman-Monteith method.Factors affecting evapotranspiration,temperature,wind speed,and sunshine hours(used in the Penman-Monteith method),increased but precipitation decreased.Using non-linear modeling methods,SPEI based on Penman-Monteith best illustrated climate changes affecting tree growth.

关键词： Climate change Drought index Hyrcanian forests SPEI'Annual growth rings fagus orientalis

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Over-mature beech trees (fagus orientalis Lipsky) and close-to-nature forestry in northern Iran

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Journal of Forestry Research 2012年第2期23卷 289-294页

作者： Mostafa Moradi Mohammad R.Marvie Mohadjer Kiomars Sefidi Mahmoud Zobiri Ali Omidi Faculty of Natural Resources University of TehranKarajIran Faculty of Agriculture University of Mohaghegh ArdabiliArdabilIran FRWO(Forests Range and Watershed Management Organization of Iran)RashtIran

Oriental Beech is the most important commercial tree species in northern Iran. In recent years wood production companies interested in felling large beech trees for profit have challenged advocates of close-to-nature silviculture who favor conservation. Our study objective was to assess the economic value of over-mature beech trees by relating tree diameter （DBH） to amount of decay. Based on the location of onset of decay, we categorized three types of decay as stump, stem, and crown decay. Trees of greater diameter （age） typically showed greater decay in the stem. Percent of decayed volume, diameter of decayed tissue, and length of decay in tree stems varied between 0.5%-64.3%, 15 cm-75 cm, and 2.0-19.5 m, respectively. With increasing trunk diameter, the propor- tion of truck decay increased. Red heart and dark red heart constituted 25% and 14.3% of sampled trees, respectively. However, we found no correlation between intensity of stem decay and morphological charac- teristics of trees. Seedlings were not abundant around the bases of over-mature trees, suggesting that the trees did not contribute to regeneration of the stand. Beech trees of diameter 〉1 m do not provide valu- able round wood for industries and cause to raise wood production costs. We recommend that these trees 〉1 m DBH should be retained in forest stands because of their low commercial value but high ecological and conservational values such as maintaining biodiversity in forest ecosystems.

关键词： Caspian forests close-to-nature forestry fagus orientalis red heart and stem decay Iran

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The effect of single-tree selction system on soil properties in an oriental beech stand of Hyrcanian forest, north of Iran

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Journal of Forestry Research 2011年第4期22卷 591-596页

作者： Kambiz Abrari Vajari Hamid Jalilvand Mohammad Reza Pourmajidian Kambiz Espahbodi Alireza Moshki Academic member of Agriculture Faculty Lorestan University Ph. D candidate of Forestry Faculty of Natural Resources Sari Agriculture Sciences and Natural Resources University Iran Forestry Department Faculty of Natural Resources Sari Agriculture Sciences and Natural Resources University Iran Research Center in Agricultural and Natural Resources of Mazandaran Province Sari Iran Ph.D candidate Soil science of temperate and boreal ecosystems Institute Faculty of forest science and forest ecology Georg-August university of Goettingen zip code:37077 Germany

A case study was conducted in beech forests of northern Iran to determine the effect of the created gaps on some soil properties in beech stand. Changes of soil properties in small （60-150 mE）, medium （151-241 mE）, large （242-332 m^2） and very large （333-550 m^2） gaps, as well as under closed stands were studied eight years after-the gap creation. Soil samples were taken from three depths, 0-10, 10-20 and 20-30 cm. The gaps were different from their around undisturbed stands in terms of the following soil parameters： Mg^＋2 concentration of 0-10 cm at medium gap size, bulk density of 10-20 cm at very large gap size as well as K^＋ and Ca^＋2 concentrations at 20-30 cm at small and large gap sizes, respectively. Furthermore, the size of the gaps had no effect on soil characteristics through the whole profile. Water saturation percent （Sp %） at 0-10cm as well as P and Mg^＋2 at 20--30 cm was different amongst undisturbed stands around different gap sizes. The center and the edges of the gap were different only in terms of organic carbon at the depth of 10-20 cm. Significant differences were observed between gaps and closed canopy regarding P and Ca^＋2 at depth 0--10 cm and 10-20 cm, respectively. It can be concluded that applied silvicultural system for harvesting trees which created these gaps might be suitable for conservation and forest management in the region.

关键词： gap soil fagus orientalis single-tree selection system northern lran

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LAI and Leaf Biomass Allometric Equations for Three Common Tree Species in a Hyrcanian Temperate Forest

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Open Journal of Forestry 2016年第2期6卷 1-7页

作者： Saleh Kahyani Hormoz Sohrabi Seyyed Mohsen Hosseini Jerry Vanclay Department of Forestry Faculty of Natural Resources and Marine Sciences Tarbiat Modares University Noor Mazandaran Iran Forest Research Centre School of Environment Science and Engineering Southern Cross University Lismore NSW 2480 Australia

Despite the importance of Hyrcanian forests for biodiversity conservation, a few studies with biomass destruction has been done to predict biomass and carbon pools from this forest and there is a lack of knowledge in our country. Biomass and leaf area index (LAI) are important variables in many ecological and environmental applications and forest management. In this paper, allometric biomass and leaf area equations were developed for three common Hyrcanian tree species, Oriental Beech (fagus orientalis Lipsky), Hornbeam (Carpinus Betulus Lipsky) and Chestnut- leaved Oak (Quercus castaneifolia C. A. Mey). To evaluate and estimate the leaf biomass and leaf area index of Oriental Beech, Horbeam and Chestnut-leaved Oak, 21, 27 and 17 individuals were selected and felled down, respectively. Tree characteristics such as diameter at breast height, total height, crown length and perpendicular diameters were measured. Destructive sampling was applied for determination of leaf biomass and LAI. Allometric equations were calculated for estimation of leaf biomass and LAI using simple linear regression and nonlinear regression analysis. The equations were compared based on several modelling parameters. Model comparison and selection were based on R2, Akaike’s information criterion (AIC), prediction error sums of squares, model standard error estimate (SEE), ΔAIC, and a correction factor. Based on the results, the mean values of leaf area, leaf biomass and LAI for Oriental Beech were 53.05 cm2, 0.176 gr, 2.16, for Hornbeam were 27.2 cm2, 0.128 gr, 1.13 and for Chestnut-leaved Oak were 62.419 cm2, 0.401 gr, 2.26, respectively. The highest significant correlation for Oriental Beech was found between LAI and total height (R2adj= 0. 931), the highest significant correlation for Hornbeam was found between LAI and Dbh (R2adj = 0. 956) and the highest significance for Chestnut-leaved Oak was found between LAI and SqrtDbh (R2adj = 0. 956). Also, the best equ

关键词： Leaf Biomass LAI Hyrcanian Forests fagus orientalis Carpinus Betulus Quercus Castaneifolia

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